We have installed two Juniper NSM 3000 devices in HA cluster with NSM 2011.1 S2 and everything is working fine.The only problem we have is this NSM configuration is not detected through https://nsmserverip/administartion/ .You can see this in the following screen
The reason for this issue is we didn't use nsm_setup to install NSM central manager or regional server.
Run the following command from your terminal after logging in as root
Save and exit the file.
Now you need to close your administration page and relogin in to administration page now you should see similar to the following screen marked with red